Field
Innovations herein pertain to computer software and hardware, computer virtualization, computer security and/or data isolation, and/or the use of a separation kernel hypervisor (and/or hypervisor), such as to detect and/or process information, including notification(s) and/or other processing regarding memory access by guest software and which may include or involve guest operating system(s).
Description of Related Information
In computer systems with hypervisors supporting a guest operating system, there exist some means to monitor the guest operating system for malicious or errant activity.
In a virtualized environment, running under control of a hypervisor, a suitably authorized guest may be allowed to monitor the activities of another guest. Among the reasons for such monitoring are debugging and security. However, previous approaches may include various drawbacks, such as allowing guests to poll the memory and other information within the monitored guest.
However, due to the constantly evolving nature of malicious code, such systems face numerous limitations in their ability to detect and defeat malicious code. One major limitation is the inability of a hypervisor to defend itself against malicious code; e.g., the particular hypervisor may be subverted by malicious code and/or may allow malicious code in a guest operating system to proliferate between a plurality of guest operating systems in the system.
To solve that issue, the motivation and use of a Separation Kernel Hypervisor is introduced in environments with malicious code. The Separation Kernel Hypervisor, unlike a hypervisor, does not merely support a plurality of Virtual Machines (VMs), but supports more secure, more isolated mechanisms, including systems and mechanisms to monitor and defeat malicious code, where such mechanisms are isolated from the malicious code but are also have high temporal and spatial locality to the malicious code. For example, they are proximate to the malicious code, but incorruptible and unaffected by the malicious code.
Furthermore the Separation Kernel Hypervisor is designed and constructed from the ground-up, with security and isolation in mind, in order to provide security and certain isolation between a plurality of software entities (and their associated/assigned resources, e.g., devices, memory, etc.); by mechanisms which may include Guest Operating System Virtual Machine Protection Domains (secure entities established and maintained by a Separation Kernel Hypervisor to provide isolation in time and space between such entities, and subsets therein, which may include guest operating systems, virtualization assistance layers, and detection mechanisms); where such software entities (and their associated assigned resources, e.g., devices, memory, etc., are themselves isolated and protected from each other by the Separation Kernel Hypervisor, and/or its use of hardware platform virtualization mechanisms.
Additionally, where some hypervisors may provide mechanisms to communicate between the hypervisor and antivirus software, or monitoring agent, executing within a guest operating system (for purposes of attempting to monitor malicious code), the hypervisor is not able to prevent corruption of the monitoring agent where the agent is within the same guest operating system as the malicious code; or the guest operating system (or any subset thereof, possibly including the antivirus software, and/or monitoring agent) is corrupted and/or subverted.
With a Separation Kernel Hypervisor, one may use a defense-in-depth technique in order to provide a runtime execution environment whereby software can securely monitor for malicious code without being affected or corrupted by it; while at the same time having close proximity (in time and space) to the malicious code (or code, data, and/or resources under monitoring).
Finally, while some known systems and methods include implementations involving virtualized assistance layers and separation kernel hypervisors to handle various malicious code intrusions, however the present disclosure is directed to innovations for handling and/or intercepting various certain specified attacks, such as those related to pages of interest.